Other consideration

If we’ll not convert the computed column formula to INT, then there will be implicit conversion, and we won’t experience any performance improvement.

If you’ll notice the datatype of input parameter then it’s INT. So either we should change the datatype of input parameter, or apply the conversion in the formula of computed column.

Here is the execution time, stats and execution plan with implicit conversion.

Conclusion

Computed Column can be used to make the queries sargeable. Sargeable query performs better by utilizing the available indexes.

We’ve also noticed, computed column alone won’t make a difference. Hence, there is a need of – search predicates to be of proper datatype, and/or the computed column should be of the proper data type, to avoid implicit conversion.